Treatment of CNS disorders Flashcards
Which channels are opened when a neurotransmitter binds on the post synaptic membrane in excitatory neurones?
And what does this cause?
Na in K out= depolarisation of the membrane
Which channels are opened when a neurotransmitter binds on the post synaptic membrane in inhibitory neurones?
And what does this cause?
Cl in = hyper polarisation of the membrane
Give an example of a glial cell:
Astrocyte
How do glial cells modulate the shape of post-synaptic response?
Remove the neurotransmitter from the synaptic cleft
Compare the following features of the Nervous system and Endocrine:
Mediator molecules
Cells affected
Time of onset of action
Duration of action
What criteria must a chemical meet before it can be called a neurotransmitter? (3)
Must be synthesised and stored within a pre-synaptic neurone (neurone must contain synthesising enzyme)
Stimulation causes release of the chemical from the nerve terminal (depolarisation)
Must cause the same effect as nerve stimulation on the postsynaptic neurone when applied directly onto the neurone
How many neuroactive substances can be found in the CNS?
Approx. 40
What type of channels are inotropic receptors?
Ligand-gated ion channels
What type of channels are metabotropic receptors?
GPCRs
List the (7) major CNS transmitters:
Glutamate
GABA
Acetylcholine
Monoamines (Noradrenaline, Dopamine & Serotonin)
Histamine
Opioids
Nitric Oxide (synthesised on demand & easily crosses the phospholipid bilayer -> its release is not Ca dependant but its synthesis is!)
What causes a neurotransmitter to have a dual response?
It acts on both Ionotropic receptors (faster inital response) AND metabotropic receptors (slower inital response because it takes a while for the second messenger to be synthesised)
What do neuromodulators do?
They alter the strength of response
What do neurotrophic factors do?
Influences neuronal differentiation and proliferation
(most do this by acting on Tyrosine kinase receptors)
What are the (4) different targets for drug action?
Ion channels
Receptors
Enzymes
Transporter proteins
Name an excitatory neurotransmitter in the CNS:
Glutamate
Name an inhibitory neurotransmitter in the CNS:
GABA
Which drug targets transmitter synthesis in the CNS?And what is the clinical application of this drug?
L- Dopa
Parkinson’s disease
Which drug targets transmitter storage in the CNS?And what is the clinical application of this drug?
Reserpine
Hypertension
Which 2 drugs targets transmitter release in the CNS? And what is the clinical application of this drug?
Amphetamine
Na & Ca channel blockers
Attention Deficit Hyperactivitiy disorder (ADHD)
Name 2 receptor agonists in the CNS?
And what is the clinical application of this drug?
Morphine (analgesia)
Buspirone (Anxiety)
Name 2 receptor antagonists in the CNS?
And what is the clinical application of this drug?
Cloazapine (antipsycotic)
Memantine (alzheimers)
Which 2 drug target reuptake in the CNS?
And what is the clinical application of this drug?
Cocaine (stimulant)
Fluoxetine (depression)
Which 2 drugs target degradation in the CNS?
And what is the clinical application of this drug?
Moclobemide (depression)
Donepezil (alzheimers)
Which drug targets intracellular signalling in the CNS?And what is the clinical application of this drug?
Lithium
Bipolar disorder
Which drug targets nerve growth in the CNS?
And what is the clinical application of this drug?
Myotrophin
Motor neurone disease
Why is it not a good idea to completely ‘knock out’ a neurotransmitter?
Give an example:
Bad side effects -> widely spread
e.g. Completely knock out glutamate = coma
Name 2 examples of drugs that target Glutamate:
(include their clinical use)
Ketamine = NMDA channel blocker (one of the inotropic receptors of Glutamate) => dissociative anaesthetic
Memantine = NMDA receptor antagonist => cognitive enhancer (in alzheimers)
What may drugs that target glutamate be used to treat? (4)
Learning and memory
Schizophrenia
Mood disorders
Excitotoxicity
Name the key 2 examples of drugs that target GABA: What are their clinical uses?
Benzodiazepines: Sedative hypnotic
Barbituates: Sedative hypnotic
Others:
Vigabatrine: GABA transaminase inhibitor = anti-epileptic
Alphaxalone: steroid general anaesthetic
Baclophen: GABA B angonist = spascticity
GHB: drug of abuse
In which (3) illnesses are GABA B recreptors for GABA targetted?
Epilepsy
Anaesthesia
Cerebral Palsy
Name the 3 main types of monoamine neurotransmitter:
Dopamine
Serotonin
Noradrenaline
N.b. these are difficult to target individually = aggressive & irritable moods if more than 1 disrupted by drug
Treatments for which 5 disorders target dopamine?
Parkinson’s disease
Schizophrenia
Drug abuse and addiction
ADHD (attention deficit hyperactivity disorder)
Depression
If drugs such as L-DOPA are given in the wrong situation what can it induce?
Schizophrenia like symptoms & hallucination
What does L-DOPA target? And what is its clinical use?
Bypasses the rate limiting synthetic enzyme for Dopamine
Parkinson’s disease
What does Haloperidol target?
And what is its clinical use?
D2 receptor antagonist
Anti-psychotic
What does Domperidone target?
And what is its clinical use?
D2 receptor antagonist
Anti-emetic
What does Selegeline target?
And what is its clinical use?
Monoamine oxidase - B inhibitor (MAO-B)
Neurodegeneration
What does Amantadine target?
And what is its clinical use?
Dopamine releasing agent
Parkinson’s disease
What does Amphetamine (methylphenidate) target?
And what is its clinical use?
Re-uptake inhibitor
Attention deficit hyperactivity disorder (ADHD)
What does Buproprion target? And what is its clinical use?
Dopamine/noradrenaline reuptake inhibitor
Anti-craving
What is Pramipexole?
Dopamine partial agonist
Treatments for which (7) disorders target noradrenaline?
Cognition
Depression
Anxiety
Pain
Addiction
Obesity
ADHD
What are the main functional effects of noradrenaline?
Attention
Cognition
Sensory
Homeostasis
Sympathetic output
Sleep-wake cycle
Motivation
What does Amitriptyline target? And what is its clinical use?
Serotonin and Noradrenaline reuptake inhibition
Pain & antidepressant
What does Reboxetine target?
And what is its clinical use?
Noradrenaline reuptake inhibition
Antidepressant
What does Sibutramine target? And what is its clinical use?
Serotonin & Noradrenaline reuptake inhibition
Anti-obesity
What does Mirtazapine target?
And what is its clinical use?
Alpha 2 adrenoreceptor and serotonin receptor antagonist
Antidepressant
What does Atomoxetine target?
And what is its clinical use?
Noradrenaline reuptake inhibiton
ADHD
What does clonidine target?
And what is its 2 clinical uses?
Alpha 2 adrenoreceptor agonist
Anti-hypertensive & epidural anaesthetic
What does Lofexine target?
And what is its clinical use?
Alpha 2 adrenoreceptor antagonist Opiate withdrawal
What are the (8) functional effects of serotonin in the CNS?
Motor control
Behavioural control
Mood and emotion
Sensory function
Homeostasis
Sleep-wake cycle
Appetite
Vomitting
Which (6) diseases are drugs that target serotonin used to treat?
Depression
Anxiety
Pain
Schizophrenia
Migraine
Emesis (vomitting)
What does Clomipramine target?
And what are its 2 clinical uses?
Serotonin reuptake inhibitor
Depression & OCD
What does Amitriptyline target?
And what are its 2 clinical uses?
Serotonin & noradrenaline reuptake inhibitor
Depression & OCD
What does Sibutramine target?
And what is its clinical use?
Serotonin and noradrenaline reuptake inhibitor
Anti-obesity
What does Fluoxetine target?
And what are its two clinical uses?
Serotonin reuptake inhibitor
Depression & eating disorders
What does Nefazedone target?
Serotonin reuptake inhibitor & Serotonin 2 receptor antagonist
What does Risperidone target?
And what is its clinical use?
Serotonin 2 receptor & dopamine 2 receptor antagonists
A-typical anti-psychotic
What does buspirone target?
Serotonin 1A receptor partial agonist
What does Sumatriptan target?
Serotonin 1B/D receptor agonist
What does Ondasetron target?
And what is its clinical use?
Serotonin 3 receptor antagonist
Anti-emetic
What does serotonin 1A receptor effect?
Mood
What does serotonin 1B/D receptor effect?
Vasculature
What does serotonin 2A/C recptor effect?
Behaviour
Why are more isoform selective drugs better?
They have fewer unwanted side-effects
What are anticholinergics used in clinically?
Parkinson’s disease
What are acetylcholinesterase (ACHE) inhibitors used for clinically?
Alzheimers disease
What is Acetylchonine involved in in the CNS?
Cognition
What are the 2 clinical uses of H1 antagonists in the CNS?
give an example
Sedation and Antiemetic(Possible role in cognition and mood)
Modafinil
Give an example of a purine (ATP) receptor anatagonist:
Caffiene
Which 3 things are purine (ATP) receptor agonists used for clinically?
Potentially:
Sedative
Anti-convulsants
Neuroprotection
What are purines (ATP) important for in the CNS?
Neuronal damage to the surrounding tissues when released (can even be neurotoxic)
What is the normal role of cannabinoids in the CNS?
Feedback loop for neurotransmitter release in synapses
What are the two types of stroke and which % of strokes do they account for?
How is each treated?
How do we determine which type it is?
Ischaemic (thrombosis) = 85%
Treatment: Anticoagulants/thrombolytics Haemorrhagic (rupture) = 15%
Treatment: Surgery to clock haemorrhage CT scan
Which artery is the most frequently effected in a stroke?
Middle Cerebral artery (a continuation of the internal carotid artery)
N.B. it is the only artery supplying this area of the brain -> blockage = death
What does an old infarction look like?
Significant tissue loss on the affected side & cystic change
Why is a lack of blood supply to the brain so detrimental?
The blood supplies O2 and Glucose to the brain tissue = metabolism -> the brain does not store glucose!
What is the treatment for a stroke?
Fibrinolytics within 3 hours = tissue plasminogen activators = improve blood flow and reduce further damage :( makes worse if due to haemorrhage!
In which 3 ways can we prevent strokes?
- controlling blood pressure
- Aspirin
- Prevent atherosclerosis (low cholestrol diet & excersize)
What is a motorneurone disease?
A chronic progressive degeneration of lower and upper motor neurones in the spinal cord, somatic motor nuclei of the cranial nerves & within the cortex (N.B. does not involve the sensory neurones)
When do motor neurone diseases onset?
Middle life